Intermediate Granite Rocks

Composition refers to a rock s chemical and mineral make up.

Intermediate granite rocks. Ultramafic rocks are dominated by olivine and or pyroxene. Mafic rocks are dominated by plagioclase and pyroxene even if you can t see them with the naked eye and smaller amounts of olivine. Felsic and mafic rocks. Granodiorite is a plutonic igneous rock formed by intrusion of silica rich magma which cools in batholiths or stocks below the earth s surface.

Typical intermediate rocks include andesite dacite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks. Syenite diorite and monzonite. These groups refer to differing amounts of silica iron and magnesium found in the minerals that make up the rocks. Other articles where intermediate rock is discussed.

Intermediate rocks are roughly even mixtures of felsic minerals mainly plagioclase and mafic minerals mainly hornblende pyroxene. Those with between 45 and 55 percent silica are mafic. And those with less than 45 percent are ultramafic. It forms from the slow crystallization of magma below earth s surface.

Granite is a light colored igneous rock with grains large enough to be visible with the unaided eye. Granite is composed mainly of quartz and feldspar with minor amounts of mica amphiboles and other minerals this mineral composition usually gives granite a red pink gray or white color with dark mineral. For igneous rock the composition is divided into four groups. In igneous petrology an intermediate composition refers to the chemical composition of a rock that has 52 63 wt sio 2 being an intermediate between felsic and mafic compositions.

Igneous rocks are classified according to their mineral content. And 65 percent silica are intermediate. Compilations of many rock analyses show that rhyolite and granite are felsic with an average silica content of about 72 percent.